Recently, various techniques for improving the fuel economy of an engine equipped with an internal combustion engine have been developed. PTL 1 discloses, as an object of “providing a vehicle control device capable of securing a long running time or a long running distance due to coasting in a running vehicle”, a technique in which, “when a vehicle speed V of the vehicle is within a vehicle speed range determined by a lower limit side vehicle speed V0 and an upper limit side vehicle speed V1, if the vehicle speed V is equal to or higher than the vehicle speed V0, the vehicle control device stops an engine by fuel cut and disengages a clutch to cause the vehicle to run by coasting, if the vehicle speed V becomes lower than the vehicle speed V0, the vehicle control device starts the engine by fuel supply and engages the clutch to perform acceleration (constant speed free run). When it is necessary to stop the vehicle, the vehicle control device stops the engine by fuel cut until the vehicle stops, disengages the clutch, and causes the vehicle to run by coasting (stop free run), and thereafter, engages the clutch to impart braking by the engine brake and the brake device. As a result, it is possible to ensure a long running time and a long running distance due to coasting and to improve fuel economy” (see abstract).
When the clutch is brought into an engaged state and the fuel supply to the engine is stopped and the vehicle is driven (hereinafter referred to as engine brake), the deceleration of the engine brake becomes an addition of engine loss (mechanical loss, intake loss, etc.) to the running resistance. On the other hand, when the vehicle is driven in a state in which the engine is stopped and the clutch is disengaged (also referred to as a stop free run in PTL 1, hereinafter also referred to as “sailing stop”), since the deceleration of the sailing stop is only the running resistance, the deceleration of the sailing stop becomes smaller than the deceleration of the engine brake.
Therefore, in PTL 1, when it is determined that there is a need to stop the vehicle and the distance up to the stop is equal to or larger than a predetermined value, first, the sailing stop is executed, and when the distance up to the stop becomes less than the predetermined value, the vehicle is decelerated with engine brake or brake (see paragraph 0066 or the like). In PTL 1, it is intended to lengthen the engine stop time and improve fuel economy by the above-described operation.